The present invention relates to fluid quick connect couplers and, more particularly, to hydraulic and pneumatic quick couplers that include features of universal couplers integrated together with features of safety couplers, in a novel universal safety coupler apparatus.
Conventional pneumatic quick coupling designs typically consist of two connecting members, including a plug member or “male” half and a socket member or “female” half. Usually, the socket member is connected to a source of pressurized fluid such as compressed air or the like. The plug member is selectively received into and locked with the socket member to complete a fluid circuit. Historically, the plugs have evolved into several “standard” configurations or profiles. Accordingly, many varieties of quick couplers have been designed, each being adapted for limited use with a different specific male plug configuration.
Several multiple interchange or “universal” couplers have been developed to accept various male plug profiles into a single specialized socket by the use of stationary and/or sliding seals or O-rings disposed in the socket. The seals or O-rings are configured to permit sealing two or more distinctly different types or styles of male plugs into a single common universal coupler. Such universal couplers are correspondingly more complex relative to couplers which are compatible with only a single male plug type.
For safety reasons and for other considerations, several types of non-universal couplers have been developed which, by means of secondary valving, allow for safe coupling and uncoupling between the respective members. These systems provide for the controlled discharge or exhaust of entrapped air to relieve applied fluid pressure between the coupler components. This style of coupler often incorporates a means of preventing accidental disconnect under pressure. Basic to this concept is the avoidance of “hose whip”. These safety features have been accomplished in existing designs by means of one or more cylindrical sleeve arrangements incorporating various sleeve locking and interlocking devices often accomplished with ball bearings. Other air exhausting safety couplers use push-button camming arrangements to permit disconnection only after a controlled venting period. It is believed that incorporation of such safety features is mandated by law in many European countries and has become widely accepted domestically.
There remains an unfulfilled need, however, for an improved coupler which combines the features of universality, i.e. compatibility of a single female socket with various male plug types, together with effective safety features in a simple, practical, and integrated package. The present invention contemplates such a universal safety coupler improvement which overcomes the aforementioned limitations and others.